Metal

Catalysis

Engineering

Pentlandite

Electrochemistry

Metallurgy

Materials science

Transition metal

Computer science

Iron sulfide

Inorganic chemistry

Chemical engineering

Ternary operation

Electrocatalyst

Physical chemistry

Non-blocking I/O

Organic chemistry

Stoichiometry

Sulfur

Cobalt

Chemistry

Programming language

Electrode

Pyrrhotite

Sulfide

Nickel

Cobalt sulfide

Nickel sulfide

CHINESE JOURNAL OF CATALYSIS (CHINESE VERSION)

Metal-rich transition metal sulfides recently gained increasing attention as electrocatalysts for the hydrogen evolution reaction (HER), as they are capable to overcome major challenges faced by sulfide-rich metal catalysts such as limited conductivity and the necessity of nanostructuring. Herein, we present the synthesis, characterization and electrocatalytic investigation of ternary metal-rich sulfide composites FexCo9–xS8 as well as NiyCo9–yS8 (x = y = 0–4.5), which possess pentlandite-type structures. In this study, we show a stepwise alteration of the binary cobalt pentlandite Co9S8 and report on the replacement of cobalt with up to 4.5 equivalents of either iron or nickel. These altered pentlandite composites facilitate the proton reduction in acidic media at different temperatures. We furthermore show that the stoichiometric variation has a decisive influence on the electrochemical activation/deactivation behavior of the catalysts under reductive electrocatalytic conditions. Here, Co-deficient composites display an improved HER performance in contrast to Co9S8. Notably, Ni/Co compounds generally tend to show higher catalytic activities towards HER than their respective Fe/Co compounds.

Fe/Co and Ni/Co-pentlandite type electrocatalysts for the hydrogen evolution reaction